Can not mount ASM diskgroup

  Hi all,

  I setup Oracle database version 11gR1 (Single) 64 bit on Linux 64 (2.6.18-164.el5)

  I use ASM to store datafile, control file ,....

  

  When start database, I meet some error:

  --------------------------------------------------------

  ORA-01078: failure in progressing system parameters

  ORA-01565: error in identifying file '+DATA/xbank/spfilexbank.ora'

  ORA-17503: ksfdopn: 2 Failed to open file +DATA/xbank/spfilexbank.ora

  ORA-15077: could not locate ASM instance serving a required diskgroup

  --------------------------------------------------------

  My ASM is local. Include two diskgroup with name are : BACKUP and DATA.

  I tried:

  $ export ORACLE_SID=+ASM

  $ sqlplus / as sysdba

  SQL> select group_number, path, mount_status, name from v$asm_disk;